Devices for delivering therapeutic energy such as an ablation device using irreversible electroporation (IRE) include a pulse generator and one or more electrodes coupled to the generator. The pulse generator delivers the therapeutic energy to a targeted tissue through the electrodes, thereby causing ablation of the tissue.
Once a target treatment area/region is located within a patient, the electrodes of the device are placed in such a way as to create a treatment zone that surrounds the target treatment region.
Prior to treatment, a treatment planning system is used to generate an estimated treatment region that completely covers the target treatment region. The estimated region is used by a physician to plan where to place the electrodes in the patient.
This can be effective when the target area is relatively small, e.g., less than 2 cm in length. However, when the target area is much larger, e.g., larger than 3 cm in length, the physician may be forced to use a large number of electrodes, e.g., 4 or more electrodes. This makes accurately placing the electrodes much more difficult as moving one electrode affects the spacing from all other electrodes.
Alternatively, the large target area can be divided into two or more smaller areas and the treatment procedure for one area can be repeated to cover the other divided areas. However, this makes the entire treatment procedure much longer. The longer procedure makes it riskier for the patient since the patient would have to stay on an operating table much longer, often with an exposed body portion to be treated. The longer procedure also makes the procedure more expensive.
Therefore, it would be desirable to provide a system and method for increasing a target tissue zone for electrical ablation for a given set of electrodes.